The more we know about chemistry, nuclear physics, and health care, the more it seems like we are threatened by unseen sources: radon from the ground and lead in paint and plastics are just a couple examples.

But scientific advances also reassure us as we come up with more devices to help us combat these unseen foes. An example is the new small, portable x-ray fluorescence spectrometer, or XRF device. This tabletop device uses x-rays to probe objects for any of the highlighted elements in the photo shown above. This includes potentially toxic chemicals like lead.

The California Department of Toxin Control recently put on a demonstration of the devices. So far, they have been used to find lead and other toxins in consumer products like toys and shopping bags.